The present invention relates to a mechanical disk brake for a bicycle, and more particularly to a mechanical disk brake for a bicycle that overcomes the problem of a locked disk brake due to an overly large friction between components thereof.
A bicycle has developed from a conventional traffic means into a means useful in many specific fields. There are more and more people using bicycles in a variety of occasions. Functional requirements for a bicycle are much more strict than ever before, particularly a good brake system that involves the safety of riding the bicycle has drawn people's high attention to it. Among different types of braking mechanisms for bicycles, there is a rim brake that is also referred to as a V-type brake. The rim brake gradually fails to satisfy the current requirements for safety in riding a bicycle, particularly a cross-country or a mountain-climbing bicycle. For a bicycle to maintain an absolutely safe braking performance and a highly sensitive mobility under very bad weather and riding environments, it is necessary to develop a new braking mechanism for a bicycle to satisfy the strict requirements. A mechanical disk brake has gradually drawn people's attention because it has been tested and proven to be safer and more comfortable for use than the V-type brake.
U.S. Pat. No. 3,878,921 discloses a brake system for a bicycle, and U.S. Pat. No. 3,927,736 discloses a disk brake for a bicycle, both of which have considerably simple structures that enable easy production and assembly thereof. However, these types of brake systems for a bicycle all are subjected to a locked brake due to an overly high friction among components thereof and are therefore very danger to bicycle riders. Another problem with the conventional mechanical disk brake for a bicycle is a weak tail braking force that could not be effectively enhanced up to date. Therefore, it is desirable to develop an improved mechanical disk brake for a bicycle to overcome the locked brake and the insufficient tail braking force.
U.S. Pat. No. 5,979,609 also discloses a disk brake for a bicycle, in which a brake disk thereof is subjected to force at both sides to enable an enhanced braking effect. However, the brake disk subjected to force at both sides tends to produce thermal strain when the disk is in a braked state over a prolonged time. To avoid this problem, the brake disk must be made of a material having good radiating capacity. In addition, this type of disk brake has complicate structure and heavy weight to increase time and labor costs for manufacturing and assembling it.
U.S. Pat. No. D419934 discloses a disk brake for a bicycle. The disk brake has the advantages of simple structure, easy to assemble, convenient to adjust and replace the brake disk, and smoothly developed braking force. However, this type of disk brake has a poorly designed force-application arm that results in uncontrollable braking force, and a return spring with insufficient elasticity that results in delayed return of brake linings. That is, this type of disk brake is less sensitive.
In addition, the steel cord employed in general mechanical disk brake, as being affected by a tension thereof, fails to enable the conventional mechanical disk brake to effectively provide an enhanced tail braking force.
It is therefore tried by the inventor to develop a new mechanical disk brake for a bicycle to eliminate the above-mentioned disadvantages.